A Comparison of the Clinical Characteristics of Intermittent Exotropia in Children and Adults

PURPOSE: The purpose of this study was to compare and differentiate the clinical characteristics of intermittent exotropia (X(T)) in children and adults. METHODS: This study included 398 patients with X(T): 360 children ranging in age from 1 to 14 years and 38 adults over 15 years of age. Patients with neurological abnormalities or developmental delays were excluded. Clinical characteristics of interest included sex, age on first visit, age of onset, type of onset, duration to surgery, family history, chief complaints, type of fixation, refractive errors, sensory tests, angle of deviation, fundus examination, oblique muscle dysfunction, and other associated ocular disorders. RESULTS: In both groups, an insidious onset was more common than a sudden onset (p=0.033). Outward deviation was the most common chief complaint in both groups, followed by photophobia in the childhood group, and diplopia in the adult group. The most common subtype of X(T) was the basic type. The mean near deviation was 23.6±7.9 prism diopters (PD) in the childhood group and 30.7±12.2 PD in the adult group (p=0.01). The mean distance deviation was 23.4±6.1 PD and 28.3±11.2 PD in the childhood and adult groups, respectively (p=0.028). The rate of fusion, measured with the Worth 4-dot test at near and distance was higher in the childhood group, as compared to the adult group (p=0.024 and p=0.048, respectively). CONCLUSIONS: Among X(T) patients, the chief complaints, angle of deviation, and Worth 4-dot tests showed significant differences between the childhood and adult groups. Therefore, these are important factors to consider when assessing adults and children with X(T).